The present invention relates to the field of treatment of contaminated or polluted natural water.
In the present specification, the term “natural water” refers to a body of water, typically outdoors, which requires treatment due to contaminations or pollutions by industrial or domestic activities, or natural phenomena. Examples of natural water include rivers, streams, lakes, reservoirs, ponds, canals, sea water in a bay, and so on. The water body may have different widths and depths, and can stay substantially still or flow at different flow rates.
In much of the industrialized regions of the world, water treatment facilities are enforced to remove pollutants such as organic wastes and toxic chemicals from the industrial and municipal waste water before they can be discharged into natural water body. However, eutrophication of natural water body becomes an increasingly important issue still as the global climate and environment change under its way. More diseases have been identified to be resulted from the eutrophication of natural water and blue green algae bloom. To improve the water quality in the natural water, various natural water management measures such as lake and pond circulator, wetland system, aerators, and etc. have been deployed in natural water bodies. These measures aim to reduce eutrophication through reducing nutrient loads, improving biodiversity and balance thus to suppress bad algae bloom in natural water.
In some developing regions of the world, due to financial constraints, low economic priority, and inefficiency in law enforcement, natural waters in these regions are sometimes severely polluted by organic wastes and toxic chemicals at levels far exceeding water's natural capability to clean itself up. The high eutrophication rate of natural waters has raised global concerns. People in these regions more frequently experienced the water resource related environmental crisis, which caused loss of sources of drinking water, shut-down of factories, evacuation of population, and many health problems. Although various measures mentioned above have been implemented but hardly in a large scale, little progress has been demonstrated largely because of the cost, technology, and engineering integration issues. In particular, a technology and apparatus that can effectively reduce Total Nitrogen (TN), Total Phosphorus (TP), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) in a part or the whole natural water body is highly desired to combat the eutrophication of natural water.